obama also had a new warning on iran's nuclear program. yesterday iranian leader ahmadinejad repeated his claim that the program is only for peaceful purposes, an explanation the u.s. and other countries dismiss. today the president said again iran cannot be allowed to build nuclear weapons. >> let me be clear. america wants to resolve this issue through diplomacy. we believe that there is still time and space to do so. but that time is not unlimited. make no mistake, a nuclear-armed iran is not a challenge that can be contained. it would threaten the elimination of israel, the security of gulf nations, and the stability of the global economy. >> woodruff: turning to the civil war in syria, the president repeated his call for an end to the bloodshed and to the regime of bashar al assad. >> if there is a cause that cries out for protest in the world today, peaceful protest, it is the regime that tortures children and shoots rockets at apartment buildings. we must remain engaged to assure that what began with citizens demanding their rights